[s-cars] Re: Musty Air conditioner

[RubEric at aol.com]

The must smell is caused by mold in the evaporator. Condensate accumulates in
the intersticial spaces of the evaporator creating ideal conditions for mold
to grow. Most of the condensate drains but some stays behind after the car is
shut down.

 The best cure is prevention and that is to not put the car away with the
evaporator cold and sweaty.  Turn off the a/c a few minutes  before you park
and place the fan on high to dry it out.  That is prevention, however, not a
cure.
Long ago, on an earlier Audi (my treasured 5KT Olympic), the smell was so
bad, I had the evaporator replaced.

Some have had marginal success with spraying lysol or other mold killing
spray thru the a/c.

Are you in a cold climate?  I think cold weather would kill the mold.